Personality traits during high school may predict later dementia risk
Personality traits exhibited during high school may be associated with dementia risk more than 5 decades later, according to findings of a retrospective cohort study published in JAMA Psychiatry.
“Certain personality traits may serve as protective factors against later life dementia risk,” Kelly D. Peters, PhD, principal psychometrician at the American Institutes for Research in Washington, D.C., told Healio Psychiatry. “These results suggest a role for personality in life course models of dementia, and highlight the importance of considering early life characteristics when evaluating dementia risk in older adults.”
According to Peters and colleagues, previous research has reported associations between personality phenotype and dementia in older adults. However, cognitive symptoms often appear many years after neuropathologic changes, which may be the root cause of altered personality, they noted. Thus, controversy persists around whether supposed dementia-prone personality profiles — low conscientiousness and high neuroticism — reflect preexisting disease or are true risk factors for later development.
The researchers examined personality during adolescence because this period has a low likelihood for preclinical dementia pathology. They analyzed data for 82,232 participants from a national sample of high school students in 1960 and identified individuals who received a dementia-associated diagnosis according to the ICD-9 between 2011 and 2013. Study participants completed a 150-item personality inventory that measured 10 personality traits and determined personality phenotype on a spectrum from maladaptive to adaptive. It also evaluated socioeconomic status, demographic factors and height and weight. Participant mean age was 15.8 years at baseline and 69.5 years at follow-up.
The researchers reported that the personality trait vigor in adolescence was associated with lower risk for dementia (HR for 1 SD = 0.93; 95% CI, 0.9-0.97) approximately 54 years later. They also found protective effects for calm (HR = 0.93; 95% CI, 0-.84-0.96) and maturity (HR = 0.91; 95% CI, 0.85-0.97). A general personality factor that included social sensitivity, calm, tidiness, culture and maturity “reflected a globally adaptive adolescent phenotype that showed a protective association against later-life dementia similar to its constituent personality traits,” the researchers wrote. They noted a more pronounced risk reduction at higher socioeconomic status.
Lower adolescent socioeconomic status may increase later dementia risk because the burdens of financial stress, transportation issues and housing problems may negate potential personality phenotype protective effects (ie, calm demeanor) on stress-related pathways associated with dementia, Peters and colleagues noted. Other associations for increased dementia risk included being older in 1960, being of African American race, being female and having a higher adolescent BMI.
“While it was exciting to see this relationship between adolescent personality and later life dementia, it remains an incredibly complex picture that raises a number of additional questions," Peters said. "I think this work sets the stage for us to explore this relationship further, to try to disentangle some of the nuances, and that’s what I’m really excited about.” – by Joe Gramigna
Disclosures: Peters reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.